Suction nozzle

Abstract

A suction nozzle includes zirconia-based ceramics. The ceramics includes first grains and second grains. The first grains each contain zirconia, and the second grains each contain a black-colored component. The suction nozzle includes a suction face and a suction hole. The suction hole is in communication with the suction face. In the suction face, an area ratio of an area occupied by the second grains to a measurement face obtained by polishing the suction face is greater than or equal to 17% but less than or equal to 34%. A number of the second grains in an area of 90 μm2 in the measurement face is greater than or equal to 150 but less than or equal to 250.

What is claimed is: 
     
       1. A suction nozzle comprising:
 zirconia-based ceramics containing:
 first grains containing zirconia and 
 second grains containing a component of a black color, 
 
 a suction face comprising a measurement face that is obtained by polishing the suction face for measurements, the measurement face having:
 a ratio of a total area of the second grains within the measurement face to an area of the measurement face of 17% to 34%; and 
 a number of the second grains in an area of 90 μm 2  in the measurement face of 150 to 250, wherein the number of the second grains is measured by an image analysis of the measurement surface; and 
 
 a suction hole in communication with the suction face. 
 
     
     
       2. The suction nozzle according to  claim 1 ,
 wherein an average of distances between centroids of adjacent second grains in the measurement face is 0.6 μm to 1.0 μm. 
 
     
     
       3. The suction nozzle according to  claim 1 ,
 wherein a proportion in number of the second grains having a grain size of 0.6 μm or more in the measurement face in terms of equivalent circle diameter to a number of all of the second grains is 25% or less. 
 
     
     
       4. A suction nozzle comprising:
 zirconia-based ceramics containing:
 first grains containing zirconia and 
 second grains containing a component of a black color, 
 
 a suction face comprising a measurement face that is obtained by polishing the suction face for measurements, the measurement face having:
 a ratio of a total area of the second grains within the measurement face to an area of the measurement face of 17% to 34%; and 
 a number of the second grains in an area of 90 μm 2  in the measurement face of 150 to 250; and 
 
 a suction hole in communication with the suction face, wherein kurtosis Rku obtained from a roughness curve in the suction face is greater than 3 and less than or equal to 4.5. 
 
     
     
       5. A suction nozzle comprising:
 zirconia-based ceramics containing:
 first grains containing zirconia and 
 second grains containing a component of a black color, 
 
 a suction face comprising a measurement face that is obtained by polishing the suction face for measurements, the measurement face having:
 a ratio of a total area of the second grains within the measurement face to an area of the measurement face of 17% to 34%; and 
 a number of the second grains in an area of  90  μm 2  in the measurement face of 150 to 250; and 
 
 a suction hole in communication with the suction face, wherein skewness Rsk obtained from a roughness curve in the suction face is greater than 0.